Well core drill



pril 28, 1936.

WELL CORE DRILL J..H. HOWARD ET Al.

Filed May 25, 1954 2 sheets-sheet 1 April 28, 19365 A J. HA HOWARD ET'AL 2,038,793

WELL GORE DRILL Filed May 25, 1934 2 Sheets-Sheet 2 f7?. 3 'g. 7 20 r AP 29 I .33 54 a7 a 4 56 58 2 E 6l 25H90 22 4 '9 4g 2623 ,Off/ll/"MM Patented Apr. 28, 1936 UNITED STATES PATENT OFFICE.

2,038,793 WELL CORE DRILLv ration of California.v

Application May 25, 1934', SerialA No; 727,498

15r Claims,

This invention relates to a drilling tooland relates more particularlyto a core drill for use in the rotarymethod of well drilling. A general object of this invention is to prov-ide a simple practical and improved rotary core drill embodying an hydraulically actuated core catcher.

Another object of the invent-iony is to provide a core drill embodying apractical andv effective corecatchingand core retaining means that does not normally-engage or in any way interfere With the core and that maybe actuated from the upper end of the Well to dependably grip and retain the core without operating or manipulating the drilling string. Another object of the invention is to provide a core drill embodying a core catcher and a iloatinginner barrelo r core receiving barrel that may be held against rotation through its engagement with the core and that is adapted to be moved longitudinally by uid under pressure to actuate the core catcher.

. Another object of the invention is to provide a core drill ofthe character mentioned including a novel and particularly effective swivel means for-.normally suspending the longitudinally shiftable inner barrel whereby it may be held; against rotation with respect to the core due to its engagement therewith.

' Another object of the invention 1s to provide a, simple, practical core catcher thatY is rotatably supported in the bit head of the drill to iloatY or be held against rotation during the drilling operationand that is actuated to grip the core by downward movement of the hydraulically actuated core barrel.

Another object of the invention is to provide acore drill of the character mentioned including asimple, dependable swivel meansfor suspendingthe inner barrel for rotation that is combined with a readily detachable, valve on the upper end ofthe inner barrel;

A further object of the invention is to provide a core drill of the character mentioned that,r involves av single dependableV latch forv releasably holding the inner barrelv in its up or unactuated position and that does not involve any-` pivoted levers, spring fingers or-complicated valves that might be rendered inoperative during the, drilling; or coring operation.

Other objects-and features-ofour invention willy be better-and more fully understood from, the following detailed description of-l typical preferred forms and applicatipns-ofthe invention; throughout which description reference may-- b e had" tod the accompanying-drawings, in which (Cl. Z55-72),

Fig. 1 is a longitudinal' detailed sectional view-l of the drill provided by this invention illustrata ingthe inner barrel and the core catcher-in their normal or unactuated positions. Fig. 2 is a viewV similar to Fig. 1 illustrating the inner barrel andl the core catcher in the unactuated positions. Figs. 3 and 4 are enlarged transverse detailed sectional views taken as indicated by lines 3-3 and 4 4, respectively,` on Fig. 1. Fig. 5 is an en-` larged transverse detailed sectional View taken as indicated by line 5 5 on Fig. 2. Fig. 6is an enlarged fragmentaryelevation of the valve mounting andA Fig. 7 isa fragmentary longitudinal sectional view of the lower portion of thedrillv illustrating a modied or alternative form of core catcher.

The core drill of the present invention includes, generally; an outer barrel I0 having a bit head II on its lower end, a core catcher I.2 in the bit headv I-.Ig a longitudinally shiftable inner barrel I3 adaptedto actuate the core catcher I2, means I 4 for releasably. suspending the inner barrel, and hydraulic means I5 for actuating the inner barrel I3;v downwardly to operate the core catcher I2. The outer barrel I0 of' the drill is adapted to be attached tothe operating or drilling string toM beA rotated.v therewith. The outer barrel I0. is an elongated: tubular memberprovided at its upper end' with a connecting member or sub I6. The sub1-.6 may have a tapered screw-threaded socket I1' in its. upper end for receiving a threaded pin part on therdrilling string for the purpose of attaching the barrel I0 to the string. A reducedlongitudinal opening I8 is provided in the sub- IIiy and terminates at' its lower end in a downwardly. facing shoulder I9. A sub or connecting member 2.0 is provided on the lower end ofthebarrel Ill to carry the bit headV I I.

The bit head II isoperable to make an annular cut in the earth formation and thus pro-V` videal corefor-reception by the inner barrel/I3. The bit head II includes a shoe or body 2-'I screwthreaded on the pin 72D@- of the connecting member- 2D. Suitable cutting parts are provided on the-bit head body 2 I. In the particular case ilf lustrated in the drawings spaced stepped blades 22-` projectfrom the body 2-I at circumferentially spaced points. The body 2I has a central long itudinal opening 23 to receive the core cut by the blades 22. An annular enlargement or recess 24' is pro-vided in the upper end of the opening 23` to receive the endr portion of the inner barrel I3.

The corercatcher I2 is; provided to grip and hold the core to break it free from the formation when the drill israised and t'o retainV the core in the barrel I3 when the drill is withdrawn from the well. The core catcher I2 is designed to be actuated by the inner barrel I3 Ywhen the inner barrel is moved downwardly by the hydraulic means I5. The core catcher I2 comprises a tubular member 25 arranged in the opening 23 of the bit head. The lower portion of the member 25 is recessed in the wall of Vthe'opening 23V at 26 and itsupper portion projectsthroughy the recess 24. Rivets 21 removably attach the member 25 to the bit head body 2l. A plurality of longitudinal slots extend downwardly through the' projecting upper portion of the member' 25 to divide it into a plurality of exible fingers 28.V Vertically spaced projections 29 areV provided on the outer side'of the fingers 28 and have bevelled upper and lower sides. The projections 29 are arranged in annular series and are adapted to be engaged by shoulders on the barrel I3 as will be subsequently described. It' is to be particularly noted that the core catcher l2 just described presentsr a smooth interior surface that is inset :from the wallV of the opening 23 so 'that' the. core catcher ,does notengage or in. any way interfere with the c ore as it passes into the drill.

The inner barrel I3 is provided to receive andv holdrthe core and in accordance with .the invention is shiftable longitudinally by the hydraulic, meansl5 to actuate the core catcher I2. The barrel I3 is arranged longitudinally in the outer barrel I and is suitably spacedfrom the interior of the outer barrel leaving an annular fluid pas-4 s age P. In practice the inner barrel I3 may have.

comparatively thin walls as illustrated to ber light inA weight and to receive a core of maximum. diameter. The inner barrel I3 extends downwardly into the bit head' II and is provided at4 its lower ythe inner barrel VI3to receive or cooperate withv the swivel means I4 for .suspending the inner.

end with an enlargement or collar 30. The collar.V Y 35 is movable longitudinally in the recess. 24 and.

has a shoulder 3I adapted to bear upwardly againstv thelower end of the pin 20a..

hard faced or provided with wearftaking. bearing ngers. The upper Walls oftherecesses 32 form shoulders 33 whichL are adaptedto engagev the projections 29 to bend or flex the lingers 28 in-fr wardly when thebarrel I3 is moved downwardlyI to actuate the core catcher. An external enlarge-f ment or collar 34 is providedon the upper end of barrel. Y

. The means I4 yrotatably suspendsthe inner barrel so that the inner barrel may be held against rotation `relative to the core during the drilling or coring and the means I4 is releasable by the hydraulic means I to permit the inner barrelY to move 'downwardly .under uid pressure to actu.- ate the core catcherY I2. The swivel'means I4in cludes a wash pipe 35'shiftable in the opening I8 of the sub I6. The wash pipe 35 is preferably keyedv to the subv I6. In the drawingswe; have shown a key 36 onthe wash'pipe 35 operating in a key-way 31 in the wall of the opening I8. The

Yopening 38 in the wash pipe is at all times in com'-- munication with the lower end of the drilling string. The upper end of the opening 38 is open tothe, interior of thedrilling string and lateral portsA 39 .are provided in the wall of the wash The. shoulder 3l and the end of the pin 2I1IBl may be.

pipe to connect the opening 38 with the space P between the two barrels. A rotatable connection or swivel connection is provided between the wash pipe'35 and the upper end of the barrel I3. The swivel connection includes a lower member 49 and an upper member 4 I. The lower Vmember 40 is arranged in the collar 34 and engages the lower end of the washpipe-35. A flange 42 is provided onthe lower end of the washY pipe 35. The upper member 4I is screw-threaded tothe member 4l) and surrounds the lower portion of the wash-pipe 35. A downwardly facing shoulder 43 is provided on the upper member 4I to engage connection between theupper swivel memberY 4I.'

and the inner barrel I4. A plurality of bayonet slots 44 extend into the collar 34 from its upper end. The slots 44 have lateral, branches or` recesses 45 at their lower ends. Ribs 46a are provided on the collar 34 toV reinforce the` collar at the bayonet slots. Y A plurality of lugs 46 are provided on the swivel member 4I to cooperate with Y turned into the recesses 45.Y A pivotedlock member V4'I normally fills one of the longitudinal portions of a slot 44 to prevent the accidental displacement of the lugs A46 from the lateralre-v cesses of the slots.

position where the projections 29 are received inV the grooves 32. The latch48 is releasable by the hydraulic actuating means I5 to allow the inner barrel I3 to be moved downwardly by fluid pres-- Y It will be seen that the l swivel connection and the bayonet slot connection sure. The latch 48 is in the form of a plunger or bolt shiftable in a lateral opening 49 in the sub Y I6. The Vouter portion ofthe opening 49 is Yen larged and is closed by a plug 50. A spring 5I is arranged under compression between the plug50 and the outer end of the latch48toyieldinglyurge Ythe latch inwardly to cooperate with the wash pipe 35. A flange 52 is provided on the latch 48 to limit the inward movement of the latch. The

latch 48 normally projects throughV an opening 53 in the wash pipe 35.to suspend the wash pipe and the inner barrel I3.`v VIn accordance with the invention the latch 48 extends completely through the opening 53 and projects into the opening of the latch 48 is sharpened or beveled as illustratedY in the drawings. IThe opening 49 is pref-v erablypacked with grease or the like.

During the drilling or coring operation circlation fluid is continuously pumped downwardly through the drilling string. .This circulation iluid passes through the wash pipe 35 and ows downwardly through the passage Pto the bit head I I.

downwardlyinto the well bore. L.It is desirablel to the member 25 described above.

to prevent the downwardly flowing circulation uid from entering the inner barrel I3. A valve seat 51 is provided in the wash pipe 35 below the ports 39 and a ball valve 58 is provided to cooperate with the seat 51 to prevent the entrance of circulation uid to the inner barrel. The ball valve 58 moves oiof the seat 51 to permit uid that may be trapped in the barrel I3 to discharge as the core is received in the barrel.

The hydraulic actuating means is operable to release the latch 48 from the wash vpipe 35 and then force the inner barrel I3 downwardly to actuate the fingers 28 of the core catcher inwardly to grip the core. The hydraulic actuating means I5 includes a valve seat 60 on the interior of the wash pipe 35 between the ports 39 and the latch receiving opening 53. 'I'he seat I6 may be in the nature o-f an internal enlargement on the wash pipe. The means I5 also includes a valve member or plunger 6I adapted to be dropped or pumped downwardly through the drilling string to iirst engage and release the latch 48 and then cooperate with the seat 68 to close the opening 38 of the wash pipe. The plunger 6I is suiiiciently long to close the latch receiving opening 53 in the wall of the wash pipe when in contact with the seat B8.

When a core of sufficient length has been received the valve memberor plunger 6I may be dropped or pumped downwardly through the drilling string to enter the wash pipe 35 and come to rest on its valve seat 60. During its movement through the wash pipe 35 the tapered or pointed end of the plunger engages the projecting end of the latch 48 to move the latch in` wardly against the action of the spring 5 I. When the latch is moved inwardly in this manner the wall of the opening 53 engages the tapered end of the latch and downward force on the wash pipe causes the latch to be further moved outwardly out of engagement with the wash pipe. When the plunger 8| is seated on the seat 60 the pump pressure on the circulation fluid in the drilling string acts downwardly against the upper end of the wash pipe 35 and the plunger 6I to force the inner barrel I3 downwardly. An area equal in diameter to the external diameter of the wash pipe 35 is acted upon by the circulation fluid.

The invention includes means for informing the driller of the full actuation of the inner barrel I3 and the core catcher I2 and for resuming the circulation of fluid through the tool. A lateral port 'I0 is provided in the wall of the wash pipe 35 in a plane above theplane of the opening 53.V Upon the inner barrel I3 reaching its lowermost position where the end of the collar 30 is at the bottom of the recess 24 the port Ill passes or partially passes the shoulder I9 to put the opening 38 of the wash pipe and the interior of the drilling string in communication with the passage P. This automatically relieves the pressure on the fluid in the string so that the pump no longer labors indicating to the driller that the tool has been fully actuated.

Fig. 7 of the drawings illustrates a form of core catcher I2@L that is free toI float or rotate in the bit head. The core catcher I2*L comprises a tubular member 25a which is similar generally The member 25a is inset in the opening 23 of the bit head and has spaced upwardly extending fingers 28a adapted to be bent inwardly against the core. The ngers 28an have projections 292L engageable by shoulders 33a on theinner'barrel to cause inward tion of the core catcher I2a and the other parts is the same as in the form of the invention illustrated in Figs. 1 to 5, inclusive, of the drawings.

The drill is run into the well on the lower end of the operating string with. the latch 48 engaging in the opening 53 to suspend the inner barrel I3 in the position where the core catcher I2 is unactuated. When the drill has reached the bottom of the well circulation fluid may be passed downwardly through the string to flush the tool of sand or solid matter. The ball valve 58 may be dropped through the string, after the ushi'ng of the tool, to come to rest on the seat 51. The circulation of the fluid may be resumed and the drilling or coring operation started. The bit head II makes an annular cut in the earth formation leaving a core which is received by the inner barrel I3. The drill is rotated in accordance with the usual practice in the rotary method of well drilling and the inner barrel I3 which is swivelly supported from its upper end may be held against rotation through its engagement with the core. This prevents the breaking or wearing away of the core through engagement with the inner barrel. The downward thrusts are transmitted from the outer barrel I D to the inner barrel through engagement of the pin 2i)a with the shoulder 2I so that the latch 28 and the swivel connection are relieved of these strains. The core catcher I2, which is inset in the Wall of the bit head opening 23 allows the core to pass into the inner barrel I3 with substantial clearance and does not engage the core. Y

When a core of suicient length has been obtained the plunger 6I is dropped or pumped through the drilling string to enter the wash pipe 35. In passing through the wash pipe the plunger 6I moves the latch 48 outwardly out of the opening 53. The plunger 3| seats or comes to rest on the seat 88 to cut off the downward flow through the drilling string. The pressure on the luid in the string then acts on the upper end of the wash pipe 35 and the plunger 6I to positively force the inner barrel I3 downwardly. The weight of the inner barrel I3 and the connected parts of course tends to move the inner barrel downwardly. Upon downward movement oi the inner barrel the shoulders 33 cooperate with the projections 29 on the ngers 28 to flex or bend the iingers inwardly into the core. The lingers 28 are capable of substantial inward movement and obtain a rm dependable grip on the core. As the inner barrel I3 reaches its fully actuated position the port Ill comes into communication with the passage P relieving the pressure on the circulation fluid to inform the driller of the full actuation of the tool. When the port 'Ill communicates with the passage P the circulation of uid through the tool is automatically resumed. Upon the drill being raised the fingers 28 which are biting into the core cause the core to be broken away from the formation and the ngers support the core in the inner barrel I3 when the drill is pulled from therweu. After the drin has been pu11ed to the surface the outer barrel l0 may be disconnected from the bit head Il and pulled upwardly from around Ythe inner barrel '|3. .The

bayonet slot connection between the swivel member 4l and the inner barrel I'3 is such that the wash pipe 35 and the parts of the swivel connection may be easily disconnected irom'the inner barrel.

Thecore drill of the present invention embodies Y a core catcher that is positively actuated by iluid under pressure acting to move the inner barrel downwardly. The invention provides a simple dependable means for swivelly suspending the inner barrel from its upper end and for releasing the inner barrelrfor downward movement bythe hydraulic means.

Having described only typical preferred forms and applications of our invention we do not wish to be limited or restricted to the specific forms and applications herein setforth, butwish to reserve to ourselves any modifications or variations that may appear to those skilled in the art or fallwithin the scope of the following claims: Having described our invention, we claim:

1. In a core drill having an outer barrel and a bit head on the lower end of the outer barrel, a longitudinally movable inner barrel within the outer barrel, means rotatably supporting the inner barrel on the outer barrel comprising a member rotatably connected with the inner barrel, and a latch connecting the member to the outer barrel, means for moving the inner barrel downwardly, and a core catcher in the bit head actuated by downward movement of the inner barrel;

2. In a core drill, an outer barrel, an inner bar- -rel movablelongitudinally inthe outer barrel,

means normally rotatable suspending the inner barrel including a releasable spring held latch, a core catcher actuated by downward movement of the inner barrel, and means for releasing the latch and moving the inner barrel downwardly.

3.' A drill including, an outer barrelY having a bit head on its lowerend, an inner barrel arranged for longitudinal movement in theouter barrel, core catching means actuated by longitudinal movement of the inner barrel, releasable means normally rotatably supporting the inner l barrel against longitudinal movement including a spring held` latch, and means for releasing the latch and moving the inner barrel longitudinally to operate the core catching means including an object to be dropped through the drilling string to cooperate 'with the latch and then transmit pressure to the inner barrel.

4. A drill including, an outer barrel having a barrelV having its lower end rotatable and longi-V tudinally movable in the outer barrel, means rotatably supporting the upper end of the inner barrel and releasably holding the inner barrel against downward movement, a core catcher actuated by downward `movementi'of thefinner bar rel, and means releasingsaid means` and moving the inner barrel downwardly.

6. A well drill for use on a tubular drilling n string including, an outer barrel to be attached to the lower end of the string, an inner barrel shiftably andV rotatably arranged in the outer barrel to receive a core, core catching means adapted to be actuated by downward movement of Vthe inner barrel, releasable means holding the inner barrel against downward movement, and means actuated by uid passed through the string to release said means and move the inner barrel downwardly. V

7. A well drill for use on a tubular drillingV downwardly, the last mentioned means including a member to be passed through the string.l

8. A well drill for use on a tubular drilling string including,.an outer barrel to be attached to the lower end of the string, an inner barrel shiftably and rotatably arranged in the outer barrel to receive a core, coreV catching means adapted to be actuated by downward movement of the inner barrel, a longitudinally shiftable member in the outer barrel, releasable means holding the member against movement, a swivel connection between the member andthe upper end of the inner barrel, and an objectto be dropped through the string to release thereleasable means.

9. A well drill for use on a tubular drilling string'including, an outer barrel to be attached to the lower end of the string, an inner barrel shiftably and rotatably arranged in the outer barrel to receive a core, core catching means adapted to be actuated by downward movement of the inner barrel, a tubular member shiftable in the outer barrel and normally passing iluid pumped through the string, a swivel connection' between the member and theinner barrel, releasable means normally holding the member against movement, and an object to be passed through the stringY to release said means and close the member whereby fluid pressure forces the inner barrel downwardly. ,Y V

10. A well drill for use on a tubular drilling string including, an outer barrel to be attached to the lowerend of the string, an inner barrel shiitably and rotatably arranged in theouter barrel toA receiveV a core, core catching means adapted to be actuated by downwardV movement of the inner barrel, a tubular member shiftable in the outerV barrel and normallyv passing iluid pumped through'the string, a swivel connection betweenV the `member and the innerv barrelQre-f leasable means normally holding the member against movement, and an object to befpassed through the string to release said means and close the member whereby fluid pressure forces the inner barrel downwardly, the memberhav ing a port opened upon actuation of theV :core catcher to resume circulation through the drill. Y 1.1., In a well drill, an outer barrel having a bit head on its lower end, a core catcher -in the bit head comprising a plurality of ngers, an inner barrel for receiving a core, means for moving the innerbarrel downwardly, `projections ony the ngers, and parts on the inner barrel cooperating with the projections upon downward movement of the inner barrel to flex the lingers inwardly.

12. A core drill including, an outer barrel, an inner core receiving barrel, and means for rotatably supporting the inner barrel including a tubular member carried by the outer barrel and having communication with its interior, a tubular assembly swivelly connected to the tubular member, and a releasable connection between the assembly and the inner barrel.

13. In a core drill, an outer barrel, an inner core receiving barrel, a tubular member connected to the outer barrel, an assembly swivelly connected to the member, a releasable bayonet connection between the assembly and the inner barrel, and a valve in the member preventing the entrance of iluid to the inner barrel.

14. In a core drill having an outer barrel and a bit head on the lower end of the outer barrel, a longitudinally shiftable inner barrel within the outer barrel, means normally rotatably supporting the inner barrel, means for moving the inner barrel downwardly, a core catcher rotatably supported in the bit head and actuated by downward movement of the inner barrel spaced opposing shoulders on the interior of the bit head, and a part on the core catcher operating between the shoulders to prevent longitudinal movement of the core catcher.

15. A well drill including, an outer barrel having cutting means on its lower end, an inner barrel having its lower end rotatable and longitudinally movable in the outer barrel, a tubular member slidable in the outer barrel, a disengageable swivel connection between the member and the upper end of the inner barrel, a releasable latch holding the member against movement and projecting into the interior of the member, a seat in the member, an object to be dropped through the drilling string to enter the member, release the latch and then come to rest on the seat to close the member whereby pressure on 9 

